Modular orthopaedic component case

ABSTRACT

A case for modular neck components for hip implants. The case may include indicators based on independent variables associated with physical characteristics of the implant, including leg length, offset, and anteversion. During surgery, the surgeon may be confronted with a need to change a preoperatively-chosen modular neck. For example, the surgeon may desire a change in at least one of the variables, e.g., leg length, offset, and/or anteversion. The case allows the surgeon to quickly and easily select a different modular neck based on an evaluation of one of the variables without requiring reevaluation of the other variables. A method described herein may include preoperative planning in which a template including a grid coordinate system is used, which advantageously provides an intuitive system for the surgeon both preoperatively and during surgery.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 11/616,369, filed Dec. 27, 2006, entitled MODULAR ORTHOPAEDICCOMPONENT CASE, which is a continuation-in-part of co-pending U.S.patent application Ser. No. 11/458,257, filed Jul. 18, 2006, entitledMETHOD FOR SELECTING MODULAR IMPLANT COMPONENTS, both assigned to theassignee of the present application, the disclosures of which are herebyexpressly incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to modular components for prostheticjoints. More particularly, the present invention relates to a case formodular neck components for prosthetic hip joints.

2. Description of the Related Art

Orthopaedic prosthetic implants are commonly used to replace some or allof a patient's hip joint in order to restore the use of the hip joint,or to increase the use of the hip joint, following deterioration due toaging or illness, or injury due to trauma. In a hip replacement, or hiparthroplasty procedure, a femoral component is used to replace a portionof the patient's femur, including the femoral neck and head. The femoralcomponent is typically a hip stem, which includes a stem portionpositioned within the prepared femoral canal of the patient's femur andsecured via bone cement, or by a press-fit followed by bony ingrowth ofthe surrounding tissue into a porous coating of the stem portion. Thehip stem also includes a neck portion adapted to receive a prostheticfemoral head. The femoral head may be received within a prostheticacetabular component, such as an acetabular cup received within theprepared recess of the patient's acetabulum.

Orthopaedic implants for hip replacement may include modular hip jointcomponents. For example, the hip stem and the neck portion with femoralhead are formed as separate components. Prior to an operation, a surgeonchooses a hip stem and a neck portion based on patient anatomy, bodyimage scans, and/or other patient-specific data. However, duringsurgery, the surgeon may discover that a different hip stem or adifferent neck portion is desired to provide more optimum results.Modular hip joint components allow the surgeon to choose a different hipstem or neck portion depending on the specific application and needs ofthe patient and surgeon. Typically, the surgeon will only change theneck portion because the hip stem is usually implanted first, andremoval of the hip stem from the femoral intramedullary canal isgenerally undesirable. Thus, the neck portion is usually the componentthat is most often changed intraoperatively. The surgeon may be providedwith a number of different neck portions to accommodate various patientanatomies.

In one known system, for example, the surgeon chooses from a pluralityof options to replace an existing neck portion with an alternative neckportion to provide the best outcome for the patient. The surgeon'schoices rely on the location of the center of rotation of the femoralhead component of the implant. Referring to FIG. 1, an image of aproximal femur 20 is shown and includes femoral head 22, greatertrochanter 24, lesser trochanter 26, femoral neck 28, and a portion offemoral shaft 27. FIG. 1 illustrates a portion 30 of a template used inthe known system. The template may also include images of the femur,similar to those described below with reference to FIGS. 3 and 4.Portion 30 of the template may be placed over the image of proximalfemur 20 acquired preoperatively to plan the optimum location of thecenter of the femoral head of the implant. Portion 30 of the templatemay include a plurality of reference points 32, 34 arranged in agenerally fan-shaped arrangement. Each reference point represents thecenter of rotation for the femoral head component of the implant.Typically, reference points 32, 34 may be based on a spherical orcylindrical coordinate system. If the surgeon desires an intra-operativechange which differs from the preoperatively chosen modular neckportion, the surgeon must simultaneously evaluate at least threevariables based on the center of rotation of the femoral head of theimplant, and may need to consult various tables to evaluate thesevariables based on physical characteristics of the patient in order tochoose an optimal implant.

SUMMARY

The present disclosure provides a case for modular neck components forhip implants. The case may include indicators based on independentvariables associated with physical characteristics of the implant,including leg length, offset, and anteversion. During surgery, thesurgeon may be confronted with a need to change a preoperatively-chosenmodular neck. For example, the surgeon may desire a change in at leastone of the variables, e.g., leg length, offset, and/or anteversion. Thecase allows the surgeon to quickly and easily select a different modularneck based on an evaluation of one of the variables without requiringreevaluation of the other variables. A method described herein mayinclude preoperative planning in which a template including a gridcoordinate system is used, which advantageously provides an intuitivesystem for the surgeon both preoperatively and during surgery.

In one form thereof, the present disclosure provides a system forfacilitating implant selection, the system including a plurality ofimplants including at least one subset in which at least one of a first,second, and third variable associated with a respective differentphysical characteristic of the implants is constant and the others ofthe first, second, and third variables vary within each subset; and atleast one case including a plurality of receptacles, each receptacleconfigured to receive a corresponding one of the plurality of implants,the plurality of receptacles configured to facilitate selection of oneof the plurality of implants based on a change in the at least onevariable.

In another form thereof, the present disclosure provides a system forfacilitating implant selection, the system including a plurality ofimplants including at least one subset in which at least one of a first,second, and third variable associated with a respective differentphysical characteristic of the implants is constant and the others ofthe first, second, and third variables vary within each subset; andreceptacle means for receiving each of the plurality of implants and forfacilitating selection of one of the plurality of implants based on achange in the at least one variable.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features of the disclosure, and the mannerof attaining them, will become more apparent and will be betterunderstood by reference to the following description of embodiments ofthe disclosure taken in conjunction with the accompanying drawings,wherein:

FIG. 1 is an image of a proximal femur, further showing a portion of atemplate of a known system overlaid on the image;

FIG. 2 is a flow chart illustrating steps of a method according to oneembodiment of the present invention;

FIG. 3 is an image of a template according to one embodiment of thepresent invention;

FIG. 4 is a perspective view of the template of FIG. 3 overlaid over theimage of a proximal femur;

FIG. 5A is a plan view of an exemplary case of modular neck componentsused in the method illustrated in FIG. 2;

FIG. 5B is a plan view of another exemplary case of modular neckcomponents used in the method illustrated in FIG. 2;

FIG. 5C is a plan view of yet another exemplary case of modular neckcomponents used in the method illustrated in FIG. 2;

FIG. 6 is an exploded view of a modular implant; and

FIG. 7 is a plan view of an exemplary embodiment case for modular neckcomponents.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate embodiments of the disclosure and such exemplifications arenot to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION

Referring to FIG. 2, a flow chart illustrating steps of method 100 isshown and includes several steps beginning with step 102. Step 102includes preparing a patient (not shown) for the surgical procedure,e.g., collecting information and past medical history. In step 104, thesurgeon or a surgeon's assistant will acquire at least one image of theappropriate portion of the hip region of the patient, e.g., at least aportion of the femur and the hip joint. The image may be a radiographicimage such as an X-ray image or fluoroscopic image, for example, or,alternatively, a computed tomography (CT) image, a magnetic resonanceimage (MRI), or any other suitable image. Typical images for a hipreplacement procedure may be taken along two different directions. Forexample, anterior/posterior (A/P) and lateral pelvic images may be takenof the hip joint.

Referring now to FIG. 3, a template 50 is shown which may be used inconjunction with the images to preoperatively plan a surgical procedurein order to perform the joint replacement/restoration. Template 50 maybe constructed of a piece of transparent plastic or other suitablematerial which may be overlaid on the image of the hip portion of thepatient. Template 50 may include a plurality of reference points 51forming a grid coordinate system, for example, a Cartesian coordinatesystem, including a pattern of intersecting horizontal and verticalindicators or lines that provide coordinates for locating points.Reference points 51 may be formed of ink deposits on the transparentplastic, or, alternatively or in combination with the ink deposits,reference points 51 may be formed as cutouts in the transparent plasticto allow the surgeon to mark directly on the acquired image where theideal center of rotation of the femoral head of the hip implant shouldbe located. The grid 52 of template 50 may include leg length beingmeasured along the “y-axis” and offset being measured along the“x-axis.” Alternatively, leg length may be measured along the “x-axis”and offset may be measured along the “y-axis.” Template 50 may alsoinclude graphic representations of a femoral stem component of hipimplant 40 (FIG. 6), i.e., stem 46 (FIG. 6), including recess 48 shownin dashed lines in FIGS. 3 and 6. The representation of stem 46 may beformed of conventional ink on the transparent plastic. A plurality orsystem of templates 50 may be provided corresponding to each availablesize or type of femoral stem component of the hip implant system.

As shown in FIG. 3, template 50 may also include reference points 54corresponding to the lateral pelvic view of the hip portion of thepatient and which represent a third axial or cylindrical componentcorresponding to the anteversion component of the hip implant. Referencepoints 54, which are arranged in three planes, may represent ananteverted neck, a straight neck, or a retroverted neck. The planes ofreference points 54 may represent the “z-axis” of grid 52 in theCartesian coordinate system, or, alternatively, the third component maybe represented in a cylindrical or polar coordinate system in which,when viewed from an end view of the proximal end of the femur, theplanes in which reference points 54 are situated are arranged in afan-shaped arrangement. More or less planes of reference points 54 maybe included to accommodate a greater number of anteversion components,if needed.

In step 106, the surgeon selects the template 50 corresponding to thefemoral stem component of the hip implant to be used in the surgicalprocedure. Template 50 may be chosen in a conventional manner such thatthe representation of stem 46 on template 50 substantially fills theintramedullary canal of femoral shaft 27 of the image, such that theactual femoral stem component of the hip implant will correctly fit theintramedullary canal of the actual femur.

In step 108 and as shown in FIG. 4, the surgeon superimposes the correcttemplate 50 on the acquired image. In step 110, template 50 may be usedby the surgeon to determine the desired leg length and offset when usingportion 50 a of template 50 corresponding to the A/P pelvic view and todetermine the desired anteversion and/or leg length when using portion50 b of template 50 corresponding to the lateral pelvic view. For thepurposes of this document, offset is measured along a line drawnsubstantially perpendicular to longitudinal axis 41 of femoral stem 46.The surgeon orients the representation of stem 46 on template 50 toalign with the intramedullary canal of the image of femoral shaft 27.When the surgeon is using portion 50 a of template 50 corresponding tothe A/P pelvic view, the surgeon orients origin 53 of grid 52 at thelocation at which the surgeon desires center 49 of head 42 of modularneck 44 (FIG. 6) to be located. This location of center 49 may notnecessarily coincide with the original center of femoral head 22 priorto surgery because the condition of femoral head 22 may dictate adifferent center for the head of the modular implant component. Forexample, if the original femoral head 22 is severely deteriorated or isbadly misshapen, the surgeon may desire a different center for the headof the modular implant than the current center for the original femoralhead 22. Also, the surgeon may wish to correct some problem, e.g.,laxity correction or bone alignment correction, which may cause thecenter for the head of the modular implant to be different than thecenter of femoral head 22. In an exemplary procedure, origin 53coincides with center 49, as shown in FIG. 4. The surgeon then assessesor evaluates where center 49 should be located on grid 52 of template50. This evaluation permits the surgeon to obtain thepreoperatively-planned values for the offset and the leg length for themodular neck component of the hip implant.

Still referring to step 110 and FIG. 4, when the surgeon is usingportion 50 b of template 50 corresponding to the lateral pelvic view,the surgeon chooses a desired anteversion component from the planes ofreference points 54. The surgeon again orients the representation ofstem 46 on template 50 to align with the intramedullary canal of theimage of femoral shaft 27, in the manner described above. The surgeonmay use the planes of reference points 54 to determine the desiredanteversion component for the modular neck of the hip implant. In anexemplary procedure, the surgeon will determine the anteversioncomponent first, and then determine the necessary leg length and offsetvalues for the preoperative plan of the procedure.

In step 110, the surgeon may mark directly on the image where center 49of head 42 of modular neck 44 (FIG. 6) will be located and/or whatanteversion component is necessary. In step 112, the surgeon thenselects a modular neck 44 from system 60 (FIGS. 5A-5C) corresponding tothe assessed variables of leg length, offset, and anteversion in themanner described below.

Alternatively, template 50 may be a template on a computer screen in acomputer assisted surgery (CAS) system. The surgeon may superimpose thecomputer generated template 50 in the CAS system on the image of theproximal femur to determine the optimal position of center 49 of head 42of a modular neck 44 (FIG. 6). In one such embodiment, advantageously,both views, i.e., A/P and lateral, may be simultaneously viewed in theCAS system and template 50 may be superimposed thereon to allow thesurgeon to simultaneously assess all three variables, i.e., anteversion,leg length, and offset.

During surgery and as shown in step 114, a preoperatively-chosen femoralstem 46 of hip implant 40 (FIG. 6) is implanted into a patient'sprepared intramedullary canal by a conventional surgical technique. Thesurgeon may then provisionally implant the preoperatively-chosen modularneck 44 (FIG. 6) which has been chosen by the surgeon to provide theoptimum result for the particular patient, in the manner describedabove. Modular neck 44 (FIG. 6) may include head 42, neck portion 43,and tapered portion 47 shaped to mate with recess 48 in femoral stem 46.Head 42 may be integrally formed with neck 44 or head 42 may be amodular component attached to neck portion 43 of neck 44.Advantageously, the femoral stem 46 (FIG. 6) of hip implant 40 (FIG. 6)is equipped to accept a number of different modular neck components.Thus, the leg length, anteversion, and offset of the hip implant can bechanged without requiring removal of femoral stem 46.

In step 116, the surgeon may trial the provisionally implanted modularneck 44 (FIG. 6) to verify or confirm the preoperative plan andassociated results. At this point, the surgeon will assess severalvariables, for example, leg length, offset, and anteversion, associatedwith the hip implant and the physical anatomy of the patient. Thisassessment may be completed via a conventional surgical technique, forexample, moving the joint through a range of motion. The surgeon mayobserve that more leg length is necessary, but that the offset andanteversion are satisfactory. The present method advantageously allowsthe surgeon to select a new modular neck based only on the change in leglength without affecting the offset and anteversion. Similarly, thesurgeon may observe that more offset is necessary, but that the leglength and anteversion are satisfactory. The present methodadvantageously allows the surgeon to select a new modular neck basedonly on the change in offset without affecting the leg length andanteversion. Because the leg length and offset changes are based on agrid coordinate system, the surgeon can easily and intuitively select anew modular neck component based on a leg length change and/or an offsetchange without requiring an extensive lookup table or complicatedmathematical conversion calculations to ensure that no other variablesare being changed undesirably.

Similarly, the surgeon may observe that a different anteversioncomponent is necessary, but that the leg length and offset aresatisfactory. The present method advantageously allows the surgeon toselect a new modular neck based only on the change in anteversionwithout affecting the leg length and offset. Because the anteversioncomponent is based on a grid coordinate system, similar to leg lengthand offset, described above, or, alternatively, on a polar coordinatesystem, the surgeon can easily and intuitively select a new modular neckcomponent based on a change in anteversion without requiring anextensive lookup table or complicated mathematical conversioncalculations to ensure that no other variables are being changedundesirably.

After the surgeon determines the desired change, the surgeon may employsystem 60 (FIGS. 5A-5C), described below, to choose a different modularneck 44 to provide more optimum results.

Referring now to FIGS. 5A-5C, system 60 is arranged to include aplurality of modular necks 44 with varying dimensions suitable fordifferent leg length, offset, and anteversion dimensions. In oneembodiment, system 60 may include container 61 with a plurality ofcompartments 63 for physically housing each modular neck 44 in system60, wherein each modular neck 44 is held in respective compartments 63and the surgeon or an assistant selects a modular neck 44 from acompartment 63 in container 61. Each neck 44 may include referenceidentifier 69. In an alternative embodiment, system 60 may be agraphical representation of the plurality of modular necks 44 arrangedin an organized arrangement, e.g., a Cartesian coordinate system. Inthis embodiment, the surgeon may select a modular neck 44 andcorresponding reference identifier 69, for example, from the graphicalrepresentation, and reference identifier 69 may then be used by asurgical assistant, for example, to retrieve the desired modular neck 44which corresponds to the surgeon's desired choice and referenceidentifier 69 from a central location at which the modular necks 44 arestored.

A subset of system 60 may be provided and arranged in container or case61. Alternatively, a plurality of subsets of system 60 may be providedand arranged in at least one container 61. System 60 is arranged suchthat all necks 44 within a given subset of necks correspond to aparticular anteversion component. Each subset may have a differentanteversion component, thereby permitting a surgeon to independentlyassess the desired anteversion component and have an identical subset ofnecks 44 for each anteversion component. For example, the anteversioncomponent may be, for example, anteverted, straight, or retroverted.Thus, for example, referring to FIG. 5A, subset 60 a of necks 44 insystem 60 may correspond to straight necks. Referring to FIG. 5B, subset60 b of necks 44 in system 60 may correspond to anteverted necks.Similarly, referring to FIG. 5C, subset 60 c of necks 44 in system 60may correspond to retroverted necks. System 60 may include as manysubsets of necks 44 that correspond to the desired number of choices ofthe anteversion component, for example, system 60 may include additionalsubsets corresponding to greater extremes of anteverted and retrovertednecks.

Still referring to FIGS. 5A-5C, for each neck 44 in each subset 60 a, 60b, 60 c of system 60, system 60 includes a pair of identifyingcoordinates corresponding to leg length and offset. For example, thenumber represented by offset component 62 corresponds to offset and thenumber represented by leg length component 64 corresponds to leg length.The Cartesian coordinates represented by offset component 62 and leglength component 64 may be represented by the following coordinates:(±offset, ±leg length). If origin 53 does coincide with center 49 duringthe preoperative planning, then the surgeon may likely choose a modularneck 44 with the following coordinates in step 112: (+0, +0). If origin53 does not coincide with center 49 during the preoperative planning dueto, for example, a defect in femoral head 22, then the surgeon maychoose a modular neck with coordinates different from (+0, +0) in step112.

Each subset 60 a, 60 b, 60 c may include two sets of pairs ofidentifying coordinates corresponding to leg length and offset. Each setcorresponds to either a right hip or a left hip. Advantageously, asshown in FIGS. 5A-5C, the surgeon need only rotate container 61 ninetydegrees to switch between a system used for the left hip and the righthip. For example, as shown in FIG. 5A, the left hip pair of coordinatesis identified by the letter L and the right hip pair of coordinates isidentified by the letter R. Furthermore, as identified at the top ofcontainer 61, the anteversion component includes a designation “right”or “left” depending on which hip those necks 44 are to be used for. Forexample, if the surgeon needs a straight neck for a left hip, then thesurgeon rotates container 61 including subset 60 a until “LEFT STRAIGHT”appears at the top of container 61, as shown in FIG. 5A, at which pointthe offset and leg length coordinates are positioned below eachrespective neck 44. Alternatively, the offset and leg length coordinatesmay be positioned above each respective neck 44.

Intraoperatively, if the surgeon does not want any change in offset butneeds a change in leg length, the surgeon will choose a new neck 44having the following coordinates: (preoperatively plannedoffset value,preoperatively planned leg length value±change in leg length) from aparticular subset according to the chosen anteversion component.Similarly, if the surgeon does not want any change in leg length butneeds a change in offset, the surgeon will choose a neck 44 having thefollowing coordinates: (preoperatively-planned offset value±change inoffset, preoperatively-planned leg length value) from a particularsubset according to the chosen anteversion component.

Advantageously, arranging the plurality of modular necks 44 in eachsubset 60 a, 60 b, 60 c of system 60 in a Cartesian coordinate gridallows the surgeon to easily and intuitively intraoperatively choose amodular neck 44 which corresponds to an independent change in leglength, offset, or anteversion. The surgeon may use a fluoroscopic orother image-guided system (not shown) to facilitate the assessment ofthe change in leg length, offset, and/or anteversion, as describedabove, or, alternatively, the surgeon may simply manually/visuallydetermine the desired change in leg length, offset, and/or anteversion,and subsequently choose a neck 44 from a subset of system 60corresponding to the desired change.

In one example, if the surgeon determines in step 116 that more or lessleg length is desired but that the offset and anteversion aresatisfactory, the surgeon may select a different modular neck 44 from asubset of system 60 which corresponds to the desired change. Forexample, if the surgeon needs no change in offset and 4 millimeters (mm)more of leg length, the surgeon chooses the neck with the followingcoordinates from a subset of system 60 corresponding to the satisfactoryanteversion component: (preoperatively planned offset value,preoperatively-planned leg length value plus 4). Subsequently, thesurgeon implants neck 44 into the femoral stem component of the hipimplant. The surgeon may similarly choose a different neck 44 dependingon how much change in leg length was desired.

In another example, if the surgeon determines in step 116 that less leglength and more offset are desired but the anteversion is satisfactory,the surgeon may select a different modular neck 44 from a subset ofsystem 60 which corresponds to the desired change. For example, if thesurgeon needs 4 mm more of offset and 4 mm less of leg length, thesurgeon chooses the neck with the following coordinates from a subset ofsystem 60 corresponding to the satisfactory anteversion component:(preoperatively-planned offset value plus 4, preoperatively-planned leglength value minus 4). Subsequently, the surgeon implants neck 44 intothe femoral stem component of the hip implant. The surgeon may similarlychoose a different neck 44 depending on how much change in leg lengthand/or offset was desired.

In yet another example, if the surgeon determines in step 116 that leglength and offset are satisfactory but the anteversion needs changed,the surgeon may select a different modular neck 44 from a subset ofsystem 60 which corresponds to the desired change. For example, if thesurgeon needs to change from a retroverted neck to a straight neck, thesurgeon will select neck 44 from subset 60 a of system 60 correspondingto a straight neck and having the desired leg length and offset.

In step 118, the different neck 44 chosen by the assessment of leglength, offset, and anteversion in step 116 is implanted into the stemcomponent of the hip implant.

Referring now to FIG. 7, another exemplary embodiment of a container ofsystem 60 is shown. Container 61′ is substantially similar to container61, described above with reference to FIGS. 5A, 5B, and 5C, except asdescribed below. Container 61′ may include a plurality of compartments63 for physically housing each modular neck 44 in system 60. Eachcompartment 63 may be slightly larger than a corresponding modular neck44 such that compartments 63 form tight tolerances with a correspondingmodular neck 44. In this manner, each modular neck 44 may only bepositioned in the corresponding correct compartment 63, i.e., modularneck 44 designated “N” may only be positioned in compartment 63designated “N”. Each compartment 63 includes indicator 70 which may beetched into container 61′ inside compartment 63. In each compartment 63,indicator 70 matches reference identifier 69 for the correspondingmodular neck 44 to be positioned in that compartment 63.

Still referring to FIG. 7, container 61′ may also include template 50′etched in at least one corner thereof. Template 50′ may be aminiaturized version of template 50 (FIGS. 3 and 4) to assist a surgeonor surgical assistant during a surgical procedure. Template 50′ maydepict a left hip joint prosthesis when etched next to the “LEFTSTRAIGHT” designation on container 61′ and, similarly, template 50′ maydepict a right hip joint prosthesis when etched next to the “RIGHTSTRAIGHT” designation on container 61′. Alternatively, template 50′ maybe adhesively attached to container 61′ or carved therein. As shown inFIG. 7, container 61′ is in a first position in which a surgeon orsurgical assistant may use container 61′ with a surgical procedure onthe left hip. Container 61′ may be rotated 90° in the general directionof Arrow A such that container 61′ is in a second position in which asurgeon or surgical assistant may use container 61′ with a surgicalprocedure on the right hip.

Container 61′ may also be divided into secondary region 78 and primaryregion 76 which are divided by boundary 80. Primary region 76 mayinclude a color, pattern, or other identifying structure on container61′ such as to identify a range of modular necks 44 which are most oftenused in a surgical procedure. Secondary region 78 identifies a range ofmodular necks 44 which are less often used in a surgical procedure. Eachcontainer 61′ for subsets 60 a, 60 b, and 60 c (FIGS. 5A, 5B, and 5C,respectively) may have a different color or other identifying structureto facilitate use with a surgical procedure.

Container 61′ may also include a plurality of removable portions ortrays 72. Each removable tray 72 may be positioned in a correspondingrecess 74 in container 61′. Removable tray 72 may include one or moremodular necks 44 which may be less often used in a surgical procedure.Removable trays 72 may be snap-fit into engagement with recess 74 whennecessary. If the modular necks 44 in removable trays 72 are notnecessary, container 61′ may be used without trays 72 positionedtherein.

Although illustrated throughout as having intervals of 4 mm for bothoffset and leg length, system 60 could be arranged to have intervals ofany dimension to accommodate the needs of a particular patient or thedesires of a particular surgeon. For example, the interval could be 1,2, 3, 4, or 5 mm, or any fraction thereof, for both offset and leglength.

The above-described concept has generally been described as a systemhaving three variables, i.e., leg length, offset, and anteversion. Thesystem has been described in which one of these three variables, i.e.,the anteversion component, is constant for any given subset of implantshaving various offsets and leg lengths. For example, the surgeon maypre-operatively choose a desired anteversion component, which may notchange intraoperatively, and then need only choose various modular necks44 from the subset corresponding to the desired anteversion component ofsystem 60 based only on offset and leg length. Alternatively, the systemmay be constructed such that leg length is the constant variable and theimplants of each subset of system 60 are arranged to have identical leglengths and varying offset and anteversion components. In anotheralternative embodiment, the system may be constructed such that offsetis the constant variable and the implants of each subset of system 60are arranged to have identical offsets and varying leg lengths andanteversion components.

Although described throughout with respect to a hip implant, the methodcould be utilized in any procedure which uses modular components, forexample, but not limited to, shoulder implant procedures, knee implantprocedures, etc.

While this disclosure has been described as having exemplary designs,the present disclosure can be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the disclosure using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this disclosure pertains and which fallwithin the limits of the appended claims.

1. A system for facilitating implant selection, the system comprising: aplurality of implants including at least one subset in which at leastone of a first, second, and third variable associated with a respectivedifferent physical characteristic of the implants is constant and theothers of the first, second, and third variables vary within each saidsubset; and at least one case including a plurality of receptacles, eachsaid receptacle configured to receive a corresponding one of saidplurality of implants, said plurality of receptacles configured tofacilitate selection of one of said plurality of implants based on achange in said at least one variable.
 2. The system of claim 1, whereinthe plurality of implants are modular components of a hip implant systemand the first variable corresponds to leg length, the second variablecorresponds to offset, and the third variable corresponds toanteversion.
 3. The system of claim 1, wherein said plurality ofreceptacles are arranged according to each said subset.
 4. The system ofclaim 3, wherein the system includes one said case per said subset. 5.The system of claim 3, wherein the system includes one said case withmultiple said subsets.
 6. The system of claim 3, wherein the systemincludes a plurality of cases, each said case including a plurality ofreceptacles arranged according to each subset.
 7. The system of claim 1,wherein each said implant is sized slightly smaller than a correspondingsaid receptacle, wherein each said implant is positionable in only saidcorresponding receptacle.
 8. The system of claim 1, wherein said casefurther includes at least one removable portion.
 9. The system of claim1, wherein each said receptacle includes an indicator and each saidimplant includes an identifier corresponding to each said indicator. 10.The system of claim 1, wherein said at least one case further includesat least one template, said template including a grid coordinate systemto assess said at least one variable, said grid coordinate system havinga plurality of reference points corresponding to at least two of thefirst, second, and third variables.
 11. The system of claim 1, whereinsaid at least one case includes a primary region and a secondary region,at least some of said plurality of implants positioned in said primaryregion, said primary region corresponding to a group of said pluralityof implants primarily utilized.
 12. The system of claim 1, wherein saidcase includes at least one anatomical structure identifier.
 13. Thesystem of claim 12, wherein said case further includes a firstanatomical structure identifier and a second anatomical structureidentifier, said first anatomical structure identifier configured foruse in a first position of said case and said second anatomicalstructure identifier configured for use in a second position of saidcase, said first position of said case oriented 90° from said secondposition of said case.
 14. The system of claim 1, wherein said caseincludes a measurement indicia proximate each said receptacle, each saidmeasurement indicia corresponding to at least two of said first, second,and third variables.
 15. The system of claim 14, wherein said pluralityof implants are modular components of a hip implant system and the firstvariable corresponds to leg length, the second variable corresponds tooffset, and the third variable corresponds to anteversion, saidmeasurement indicia corresponding to leg length and offset.
 16. A systemfor facilitating implant selection, the system comprising: a pluralityof implants including at least one subset in which at least one of afirst, second, and third variable associated with a respective differentphysical characteristic of the implants is constant and the others ofthe first, second, and third variables vary within each said subset; andreceptacle means for receiving each of said plurality of implants andfor facilitating selection of one of said plurality of implants based ona change in said at least one variable.
 17. The system of claim 16,wherein the plurality of implants are modular components of a hipimplant system and the first variable corresponds to leg length, thesecond variable corresponds to offset, and the third variablecorresponds to anteversion.
 18. The system of claim 16, furthercomprising indication means for indicating a corresponding location ofeach said implant with respect to said receptacle means.
 19. The systemof claim 16, further comprising assessment means for assessing said atleast one variable.
 20. The system of claim 16, further comprisinganatomical indication means for indicating an anatomical structureassociated with said plurality of implants.